Current-collecting device for dynamo-electric machines.



J. G. ZIMMERMAN. CURRENT COLLECTING DEVICE FOR DYNAMO ELECTRIC MACHINES.

. APPLICATION FILED MAY 17, {912. 1,055,963;

I 1/ 11/ no lyll/lll I 4,1,, 0% val/ml, 0 /1 0/ UNITED STATESI PATENT otFFroia.

sums e. znrmnmuan; or MILWAUKEE, Wisconsin, assumes no Anus-owners oom'am', A coaroaa'rron or NEW .masnr.

CURRENT-COLLECTINGDEVICE son nvnammnniso'rarc men Inns.

Specification of Letters Patent.

Patented Mar. 11, 191a. 1912. Serial No. 897,893.

To all whom it may concern:

Be. it known that I JAMES G. ZIMMEB- MAN, acitizen of the 'i'Jnited States, residing at Milwaukee, in the county of Milwaukee and State of Wisconsin, have invented certain n w and useful Improvements in, Curren Collecting Devices for Dynamo-Electric Machines, of which the following is a full, clear, and exact specification;

This invention relates to means for maintainingbrushes in contact with their cooperating commutator or collecting surface, for keeping the brushes and 'commutators cool,and .for overcoming sparking between brushes and commutators. y

In the operation of d namo-electric'machines, and especially 0 high speed dynamo-electric machines, more or less of a problem is encountered in rovidin for maintaining current-collectmgbrus es in .con-' tact at all times with the commutator.

This is especially true where the commutator surface is rough. If the brushes jump or dance ontheicommutator surface more or less sparking, which may prove serious, is occasioned. Again, dust or particles of brush which have been worn away collect 'on the surface ofthe commutator, and in this'way roduce more or less sparking. At

. the sameyime special care has to be taken to keep the commutator and brushes in a cool condition to render efiicient operation of the dynamo-electric machine.

It is therefore. the object of my invention to maintain the brushes of dynamo-electric machines 11 contacqwith the commutator or currentlecting surface, to keep the commutator can, and'maintain the commutator and brushes 0001 under all conditions of operation: These objects are accomplished by providin a brus having an opening which exten s to the commutator or ourrent-collecting surface and is connected to a means for exhausting air for not only drawing foreign and spark-producing articles away from the commutator sur ace, maintaining the onmmutatm' and brush in a same creasing the efl'ect of the pressure on theoutside of the brush tending to .hold the brush in engagement withthe commutator under all conditions of operation.

The invention is illustrated, on the accompanying sheet of drawings, in which Figure 1 is a brush and brush holder embodying my invention; Fig. 2 is a sectional view 0 my brush taken along the line 22 of, Fi 1; Fig. 3 is a sectional view of the rush taken along the line 3 -3 of Fig. 2; and, Fig. 4 is an elevation, parts being in section, of adynamo-electric machine equipped with m brush and brush holder rigging, the brus es being connected to a means for exhausting air. The various novel features of my invention will be apparent from the description and drawings, and will .be Particularly set forth in the appended'claims;

For the sa e of illustration, my invention is shown in connection with a direct current dynamo-electric machine 10 having a commutator 11a ormally eng d by brushes 13." Each tbgush is preferab y rovided witl an :9 "nin 14 exten ing through the centra portion, of the brush and comm'uniea'ti with the comparatively small opening 15 in the member 16 formed in the rush. .This member 16 is adapted to receive one end of a flexible hose or tube 17, the other end ofwhich is connected to 'a hollow stud 18. ,The brush holder 19, in-

hollow studs is connected by a curved tulTe" 22 to a hollow annular member 23 which is supported by a bracket 24 secured'to one bearing pedestal 25. This hollow annular member 23 is connec ed bv h w members comn'iutator.

or tubes 26 to a vacuumreccptacle or chamber 27, the reduction of air pressure-in which jismaintaincd by any suitable source, as a motor driven air pump 28.

Bearing upon each of the brushes 13 is a spring-pressed follower 29 adapted to yieldinglyhold thebrushes in contact with the under certain conditions of operation-the spring-pressed follower does not respond quickly enough to the inaccuracies of the commutator surface. For. this reason the brushes dance more or less upon the commutator, especially if the comn'iutator surface is more or less irregular. By means ofthe hollow portion lat of the brush being connected through hollow members-16, 1 7, 18, 22, 23, and 2G to the vacuum chamber 27 inwhich there is a relatively low fluid pressure, a corresponding low fluid pressure is ma1n-,

taincd within the-hollow brush 13. This means that the pressure of the air on the outside of the brush is greater than the pressure within the brush. This diflerence in pressure causes the brush 13 to remain in contact with the commutator far better than it would if only a spring-pressed follower wereemployed. .At the same time dust particles or spark-producing particles which may have collected on the surface of the commutator 11, are drawn'through the ho]- low brush and taken-away from the surface of the commutator to prevent sparking from this source. By this continual drawing or sucking action. away from. the commutator through the hollow brush, the commutator and brush are maintained in a cool and economical operating condition.

As here shown, the lower part of the brush is provided with an opening which extends from the bottom of the brush to a point beyond the middle of the brush, the opening being comparatively wide in one directionv and narrow in another direction. In other words. the brush may be-cored, the core being in theform of a rectangular prism the height of the prism being the greatest dimension, the .width being less than. the height and the thickness of the prism be ng very muchless than the width of the .lhcse dimensions, may, however, be

prism varied, depending upon the requirements.

The member 16, whi h is formed in the brush. is ,oix-t'erahlupf metal and 1s--T- shaped in. 'tion, tie main leg'being hol lowed or in t-HU form of a tube which communicatcs with the low pressure source through the various interconnecting hollow members.

There may he various modifications and arrangements other than that here specificallv shown and described, audit is my in mntion to cover all such modifications and As is well known, however,-

arrangements which do not involve a depai ture, from the spirit and scope" of the invention as set forth in the appended claims.

What I claim as new is: 1. A brush for dynamo-electricmachines having an air passageway therethrough.

2. A. brush for dynamo-electric machines having 'an air passageway extending therethrough, part of said air passageway being restricted. i i

3. A brush for. dynamo-electric machines having a hollow portion and a member located within said hollow portion having an opening completing an air passageway through said brush.

4. A brush for'dynamo-electric machines having a. prismatic hollow portion and a restricted opening forming an air passageway through said brush.

p 5. In combination, a hollow brush, a brush holder in which said brush is inounted, a hollow stud upon which said brush holder is mounted, and a hollow member ex-.

8. In ombination, a hollow brush for'dynamo electric machines, a holder for said brush'havi'nga hollow portion connected with the hollow portion 0t said brush, and means fori producing a reduction of fluid pressure in said hollow brush to cause a flow of fluid from'said brush through said hollow membertosaid means. w

9. In combination," a commutator; a hol low brush adapted to engage said commu- 'tat or, and means for creating: areduction of air pressure in"said"brush' to cause air exterior to said'brush to assist in yieldingly holding said brush 'mutator.

"liavin'g a hollow'portion. and adapted to engage said commutator, a means for produc' ing a. reductionin fluid pressure, and a c0mv municative connection between said hollow hrush ancl means for causing a suction from.

said hollow .brush to said means.

l'1-.-.;In combination, a dynamo electric machi,ne hayinga commutator, hollow l0. In combinatiorha commutator, a brush in contact with said com- 'brush esadaptedto' engage said commutator,

brush holders inwhich said brushes are mounted, hollow studs upon which said brush holders are mounted, a support for said studs, a mean v for producing a reduc- Milwsukee, Wis, May 13, 1912.

tion in fluid pressure, and communicative In testlmony whereof I affix my signature, connections from said means through said in the presence of two witnesses.

hollow studs and brushes to cause a suction JAMES G. ZIMMERMAN. 5 from said hollow brushes to said means Witnesses:

thereby causing a reduction of fluid pres- CHAs. L. BY'RON,

sui' within the hollow brushes. 7 Ben. E. STOLL. 

